Numerical investigation on the aerodynamics of a simplified high-speed train under crosswinds

• Large eddy simulation (LES) results of two typical yaw angles of side flow around a high speed train model are provided.
• Mean and root-mean-square (RMS) values of the lift and side forces increase as the yaw angle increases.
• The dominating frequency range increases as the yaw angle increases.
• Three-dimensional vortical structures are distinct for the two cases.
• The side force is mainly determined by the lee-side wake vortices, and the lift force is related with the roof-side flow separation.

The yaw effect of the side flow around a high-speed train is studied by means of large eddy simulation at two typical yaw angles of φ=30°φ=30° and 60°, respectively. Both the mean and fluctuating values of lift force and side force coefficients increase obviously as the yaw angle increases. The spectral analysis indicates that the time-dependent aerodynamic forces are dominated by several energetic frequencies and the frequency range is broadened to a higher extent for the large yaw angle. To have a better understanding of the train aerodynamic behaviors, the dedicate three-dimensional vortical structures are analyzed for the flow at the two yaw angles. Moreover, the time-averaged flow patterns, turbulent statistics and the surface forces are also studied on sectional planes along the train.